Answer:
4%
Step-by-step explanation:
Volume of sphere
v = (4/3)πr^3
Volume moon/ volume planet
We don't actually need the numeric value of the radius
just the 35% ratio
Radius of moon = .35 radius of planet
Vm/ Vp = (4/3)π(.35r)^3 / (4/3)π(r)^3
Cancel like terms
Vm / Vp = .35^3
Vm / Vp = 0.042875
Expressed as a percentage
Vm / Vp = 4.2875%
Rounded
Vm / Vp = 4%